Overview
The Zamzummims were a race of giants living in the land that would become Ammon. Like other giant peoples mentioned in Scripture (Anakim, Rephaim, Emim), they were displaced by other nations as God sovereignly directed the settlement of Canaan and surrounding territories. Moses recalled this history to encourage Israel that God had similarly removed powerful enemies before them.
Key Scriptures
"(The Emim formerly lived there, a people as great and numerous and tall as the Anakim. Like the Anakim, they are also counted as Rephaim, though the Moabites call them Emim.)" (Deuteronomy 2:10, ESV)
"The Ammonites call them Zamzummim, a people great and numerous and tall as the Anakim; but the LORD destroyed them before the Ammonites, and they dispossessed them and settled in their place." (Deuteronomy 2:21, ESV)
Application
Trust that God's purposes will be fulfilled regardless of obstacles or opposition we face, as He has demonstrated throughout history.